Display screen or portion thereof with a graphical user interface



FIG. 1 is a front view of the display screen or portion thereof with icon, according to a first embodiment; and

FIG. 2 is a front view of a second embodiment thereof; and,

FIG. 3 is a front view of a third embodiment thereof.

The two outer broken lines illustrate a display screen and form no part of the claimed design. The remaining broken lines illustrate portions of the graphical user interface and form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a graphical user interface, as shown and described. 